Adapter fitting



FIG. 1 is a perspective view of an adapter fitting;

FIG. 2 is a front view thereof;

FIG. 3 is a side view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a bottom view thereof; and,

FIG. 6 is a cross-sectional view according to line 6-6 as indicated in FIG. 4. 

CLAIM The ornamental design for an adapter fitting, as shown and described. 